The invention relates to a rotary feeder for removing individual blanks from a stack, which operates by positioning a row of suckers against the blank at the front of the stack in the course of an at least partial rotary movement and then moving these suckers in a continuation of the rotary movement to a conveyor for transporting the individual blanks away.
Blanks are taken to mean sheets, cartons or similar objects which are subsequently processed, formed or treated in some other way. The packaging industry is a major application area for such feeders. In this case the blanks are formed into folding cartons, filled with a product and then closed.
In a process used in practice, the front blank of a stack of blanks is positioned at an acute angle to a conveyor located below the stack. An oscillating rotary feeder, which uses suckers to take hold of the blank at the front of a stack of blanks and turns to place the blank on the conveyor, is provided in the area of this acute angle. Only a relatively small number of blanks (for example 100 blanks/minute) can be fed by such a process, which is attributable to the fact that the return movement of the feeder rules out an increase in output.
A solution has also been used which involves stopping the rotary movement of the rotary suckers so that the latter can take hold of the blank at the front of a stack and then feed the blank to a conveyor in a continuation of the rotary movement. Such arrangements are not, however, capable of producing major increases in blank feeding output either.